Cleaning Systems

ACC Cleaning System

In the power industry, the reduced availability of water as the cooling medium for the condensation of exhaust steam, combined with an increased emphasis on environmental considerations, has made the selection of an air-cooled condenser a viable alternative to the traditional steam surface condenser.

The external surfaces of the finned tubes on the air-cooled condenser are prone to environmental pollution ranging from industrial soot to leaves to bird feathers and droppings, which can adversely affect the airflow around the tubes, reducing the unit's efficiency.

Keeping the finned tube surfaces of your air-cooled condenser or fin fan unit clean is imperative to maintaining optimal performance and reliability. It is the Cleaning System job to affectively clean the surface of the heat exchanger without causing any damage.

Mechanism of ACC Cleaning System        

The external surfaces of the finned tubes on air-cooled condensers are very prone to fouling from pollen, dust, insects, leaves, plastic bags, bird carcasses, etc. Not only is the airflow affected but also the heat transfer coefficient, the deterioration in performance increasing unit operating costs. In severe cases, fouling can also limit the power generation capacity of the turbo generator.

Further, under high ambient air temperatures, operators will sometimes spray water on the heat exchanger to reduce surface temperature. Unfortunately, depending on the quality of water used, this sometimes leads to a new scale formation on the tube fins. The Cleaning System uses water at a pressure that, while allowing for effective surface cleaning, avoids damaging galvanized surfaces and fins.

 

Optimal performance and reliability of air cooled condensers and heat exchangers are highly depended on the finned tube surfaces or fin fan unit cleaning. Units fouled with dirt, dust, impurities and other deposits have reduced efficiency. By ambient temperatures increase, the negative effect of surface fouling will cost even more.
Utilizing the KARAJET cleaning systems in refineries, power and petrochemical plants, air cooled condensers and heat exchangers will work more effectively and safely.
Using our cleaning systems will cause to significant improvement in unit performance:

-Fan speed reductions by up to 50%
-Steam throughput per hour increased by 30%
-Pressure drop across unit by 30%

-Output increased (in MW) by up to 20%

What are the main components? 

The main components of the system include a nozzle beam, a tracking system, and a control panel. The water contains no additives. The nozzle beam is optimally matched to the tube bundle geometry, with a constant jet angle. Optimizing the geometry of the nozzle beam involves determining the proper nozzle distance to the surface, the jet energy and the selection of the appropriate nozzle design. The constant jet angle also ensures that there is no damage to or snapping off of tube fins, regardless of the material from which they are fabricated.

Furthermore, the carriage on which the nozzle beam is mounted moves at a constant speed and so allows the fouling to be removed effectively and uniformly across the heat exchange elements of the condenser. Because the fouling material is removed, air flow is no longer obstructed.

Applications of ACC Cleaning System

Cleaning the exterior of finned ACC tubing must be undertaken periodically to maintain optimal unit performance. Well-designed approaches for timing and implementing the cleaning must be determined and enacted. ACC operators must be diligent to optimize heat transfer by addressing manageable issues that degrade performance.

Data from several power plants equipped with air-cooled condensers show that, after cleaning to remove external fouling, it was possible to operate the unit with the fans running at half-speed rather than full-speed.

The automated cleaning system can be applied in three principal forms:

1. Permanently installed system complete with PLC controls, one system being supplied for each side of the condenser.
2. Semi-automatic system in which only the guide rails are permanently installed, the nozzle beam carriage being moved from section to section as the cleaning progresses.
3. Portable service unit, together with a portable nozzle beam carriage and control unit. The cleaning service is performed in-house or by a qualified service provider.

Advantages:

1. Cleaning can be performed during operation while the unit is still on-line.
2. No need for scaffolding
3. Labor requirements are minimized.
4. Long lifetime
5. Fan speed reduction by up to 50%
6. Steam throughput per hour increased by 30%

Limitations:

1. Uses a significant volume of water
2. Must be designed base on each ACC system as fin placements are different.

If you want to know more about this equipment,we suggest you to read our catalog here : 

KARAJET cleaning system Catalog